The main objective of this trial is to assess the efficacy and safety of propranolol in middle cerebral artery stroke patients. The primary hypothesis is as follows: Early administration of propranolol reduces the frequency of cardiovascular and/or neurological complications including vascular death in the first 30 days after acute ischemic stroke. Secondary hypotheses are as follows: Early administration of propranolol improves neurological and functional outcome of patients with acute ischemic stroke. Early administration of propranolol reduces post-stroke immunodepression and therefore lowers the rate of pneumonia after acute ischemic stroke, without increasing the frequency of auto-aggressive, CNS antigen-specific T cells. Early administration of propranolol influences alterations in cardiologic, electrophysiologic phenomenons as a reaction to autonomic dysregulation after acute ischemic stroke. Early administration of Propranolol reduces growth of infarct as determined by MRI examinations in the first 6 days.